package org.yao.netty.echo;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * Sends one message when a connection is open and echoes back any received
 * data to the server.  Simply put, the echo client initiates the ping-pong
 * traffic between the echo client and server by sending the first message to
 * the server.
 */
public final class EchoClient {
  static final boolean SSL = System.getProperty("ssl") != null;
  static final String HOST = System.getProperty("host", "127.0.0.1");
  static final int PORT = Integer.parseInt(System.getProperty("port", "8007"));

  public static void main(String[] args) throws Exception {
    // Configure the client.
    EventLoopGroup group = new NioEventLoopGroup();
    try {
      Bootstrap b = new Bootstrap();
      b.group(group)
          .channel(NioSocketChannel.class)
          .option(ChannelOption.TCP_NODELAY, true)
          .handler(new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) throws Exception {
              ChannelPipeline p = ch.pipeline();
              p.addLast(new EchoClientHandler());
            }
          });

      // Start the client.
      ChannelFuture f = b.connect(HOST, PORT).sync();

      // Wait until the connection is closed.
      f.channel().closeFuture().sync();
    } finally {
      // Shut down the event loop to terminate all threads.
      group.shutdownGracefully();
    }
  }
}